Update audio code to use size_t more correctly, webrtc/common_audio/ portion.

webrtc/common_audio/real_fourier.h

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 21 matching lines @@
   // The alignment required for all input and output buffers, in bytes.
   static const int kFftBufferAlignment;
 
   // Construct a wrapper instance for the given input order, which must be
   // between 1 and kMaxFftOrder, inclusively.
   static rtc::scoped_ptr<RealFourier> Create(int fft_order);
   virtual ~RealFourier() {};
 
   // Helper to compute the smallest FFT order (a power of 2) which will contain
   // the given input length.
-  static int FftOrder(int length);
+  static int FftOrder(size_t length);
 
   // Helper to compute the input length from the FFT order.
-  static int FftLength(int order);
+  static size_t FftLength(int order);
 
   // Helper to compute the exact length, in complex floats, of the transform
   // output (i.e. |2^order / 2 + 1|).
-  static int ComplexLength(int order);
+  static size_t ComplexLength(int order);
 
   // Buffer allocation helpers. The buffers are large enough to hold |count|
   // floats/complexes and suitably aligned for use by the implementation.
   // The returned scopers are set up with proper deleters; the caller owns
   // the allocated memory.
   static fft_real_scoper AllocRealBuffer(int count);
   static fft_cplx_scoper AllocCplxBuffer(int count);
 
   // Main forward transform interface. The output array need only be big
   // enough for |2^order / 2 + 1| elements - the conjugate pairs are not
   // returned. Input and output must be properly aligned (e.g. through
   // AllocRealBuffer and AllocCplxBuffer) and input length must be
   // |2^order| (same as given at construction time).
   virtual void Forward(const float* src, std::complex<float>* dest) const = 0;
 
   // Inverse transform. Same input format as output above, conjugate pairs
   // not needed.
   virtual void Inverse(const std::complex<float>* src, float* dest) const = 0;
 
   virtual int order() const = 0;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_COMMON_AUDIO_REAL_FOURIER_H_